I'm running one like that right now too. In fact all the tab material is missing on mine. I think the main thing that shelf does is to keep the chain from falling off the crank sprocket while you are installing it. I fumbled the cam gear while I was installing the cam with the result that my chain came off the crank sprocket. I had to pull the timing cover back off to be able to see that the reference mark on the crank sprocket was still aligned with the reference link on the chain. -- Matt

'89 4runner SR5, 3.0, auto (fun)
'93 xtra cab, dlx,3.0, 5spd (work truck)